The 6SJ7 is a pentode and is strapped as a triode I believe in this design, the 6SN7 is a dual triode so potentially could also be strapped to a single triode and used in the driver position via an adapter. Not sure how it would sound though, as the operating point would likely be different...

Unfortunately no further answer to the date codes! Would also like to know if anyone else has further insights :)

Send me a PM- might be able to help you out with that :D

Been a bit quite here recently! Here is a really interesting find today on this pair of Mullard 6J5G. The construction looks identical to the MOV L63/6J5G we know and love, with the grey glass and the distinctive top mica construction as viewed from the top. But I've never seen them with brown...

Seconded for the RCA6AS7G. One of my favourite pairings with my HD800, the warmth balanced out very nicely with the HD800, I dont feel you lose much detail if at all. Another option to try if you have it is the GEC 6080, will give even more liquid mids. EF86 would be a good choice for inputs...

Another important thing to note- British AVO tester manuals also quote new values with precise parameters for heater, anode, grid voltages instead of bias points. These parameters set up the test at a singular point chosen from/corresponding to a specific point of tube operating curves on...

Anyone know of a place to get 90 degree octal socket savers/adapters? Have a friend wanting to use 6J5s in place of 6SN7 but their amp doesn't fit the adapter in the current configuration!

6CG7 is electrically equivalent to the 6SN7 in a 9 pin envelope, so should be fine as long as the adapter is the correct pinout. I used an ECC88 --> 12AU7 adapter as they have the same pinout 6CG7 and ECC88.

That certainly looks like a good option too! When applying heat with the iron, do you just do it to the top, or from underneath on the 'male' pins of the socket saver?

That looks like what I had in mind/looking for, but 'flying lead adapter' wasn't coming up with anything on ebay. Thanks!

So I've just grabbed some flying lead CV4038 (normal version is the CV4079/A2293). Anyone have any experience soldering 9 pin flying leads into bases? Not sure what parts I should use for the base+ any tricks to getting it done. I've got maybe 2.5cm on the leads to work with.

Those are definitely not 421A, and as said above they are TS 7236 tubes. They sound great, but perhaps not for that price!

I'll go backup on some tubes if you need to split for sale as well :)

Hi LordGwyn, yes after some experimentation it seems outputs are being taken off the output capacitors, as there is no sound without power tubes- good to know and thanks for the explanation! :( I had a 6C4 tube testing better than ever on my tester and the filament burnt out as soon as I...

A few quick question about the preamp out function on the GOTL I've always wondered about- does the signal go through only the 6SN7 slot/driver tube, or does it go through the power tubes as well? I.e. would changing the power tubes when just using preamp out change anything? And would that be a...